Effect of oral iron supplementation during pregnancy on maternal and fetal iron status

The known increased need for iron during pregnancy appears to be met only in part by increased iron absorption and amenorrhea. Considerable demands are made on maternal iron stores and, since many women lack sufficient storage iron, pregnancy may be expected to cause iron deficiency. This may lead to anemia in pregnancy and post partum and could also have a bearing on the iron status of the fetus and the neonate. Based on these considerations, prophylactic supplementation of dietary iron is advocated but remains a disputed issue. In the present controlled, prospective and longitudinal study changes in hematologic status, and in particular in iron stores, during pregnancy were investigated in 44 healthy Caucasian women with uncomplicated pregnancies and deliveries. They were randomly assigned to a study group (n = 21) receiving oral iron supplements from the 16th week of amenorrhea until 6 weeks post partum, and a control group (n = 23) without iron supplementation. Maternal concentrations of hemoglobin, serum iron, serum transferrin and serum ferritin were determined at 16, 28 and 36 weeks of amenorrhea, at delivery, and 6 and 12 weeks post partum. The same variables were determined in cord blood. Iron supplementation appeared to prevent the physiologic fall in hemoglobin and serum iron concentrations which occurred in the control group, but had little influence on the observed rise in transferrin concentrations. Ferritin levels in serum, which are known to reflect mobilisable iron stores, fell to 30% of the initial values in the control group and to 70% in the study group. Six and 12 weeks post partum ferritin levels were still low in the nonsupplemented group (Tab. I).(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of oral iron supplementation on zinc and magnesium levels during pregnancy

Serial changes in serum zinc and magnesium concentrations have been studied before conception, throughout pregnancy and at 12 weeks postpartum in 15 normal healthy women not receiving iron supplementation, 10 women receiving iron supplementation but otherwise having healthy pregnancies and five insulin-dependent diabetics who also received oral iron. Relative to pre-pregnancy values zinc concentrations progressively decreased throughout pregnancy reaching a nadir at 36 weeks gestation followed by an increase; pre-pregnancy values were achieved by 12 weeks postpartum. Magnesium concentrations also decreased throughout pregnancy reaching a nadir at 32 weeks gestation increasing thereafter again with pre-pregnancy values achieved by 12 weeks postpartum. Iron supplementation in non-diabetic and diabetic women had no significant effect upon the changes in serum concentration of either zinc or magnesium. These results suggest that the decrease in the concentrations of both elements is a normal physiological adjustment to pregnancy and that iron supplementation does not influence these changes.     

The effects of oral iron supplementation on zinc and magnesium levels during pregnancy

Summary. Serial changes in serum zinc and magnesium concentrations have been studied before conception, throughout pregnancy and at 12 weeks postpartum in 15 normal healthy women not receiving iron supplementation, 10 women receiving iron supplementation but other-wise having healthy pregnancies and five insulin-dependent diabetics who also received oral iron . Relative to pre-pregnancy values zinc concentrations progressively decreased throughout pregnancy reaching a nadir at 36 weeks gestation followed by an increase; pre-pregnancy values were achieved by 12 weeks postpartum. Magnesium concentrations also decreased throughout pregnancy reaching a nadir at 32 weeks gestation increasing thereafter again with pre-pregnancy values achieved by 12 weeks postpartum. Iron supplementation in non-diabetic and diabetic women had no significant effect upon the changes in serum concentration of either zinc or magnesium. These results suggest that the decrease in the concentrations of both elements is a normal physiological adjustment to pregnancy and that iron supplementation does not influence these changes     

Maternal serum folacin levels during and after normal pregnancy

Maternal serum folacin levels decrease during pregnancy. This decrease could not be explained by hemodilution. Postpartum levels did not increase significantly compared to values measured at partum. In a healthy Dutch pregnant population receiving no vitamin supplementation the folacin status is at risk and after pregnancy it takes considerable time to refill folacin stores.     

Effect of vitamin/mineral supplementation on calcium, magnesium and iron levels in amniotic fluid and serum taken from women during first half of pregnancy

The levels of calcium, magnesium and iron in amniotic fluid and serum taken from women during first half of pregnancy were compared. The relationship between these levels and vitamin-mineral supplementation was also estimated. There was similar calcium and magnesium concentration in the serum and amniotic fluid. The concentration of iron in serum was four times as large as in amniotic fluid. Any influence of supplementation on concentration of studied minerals was noted.     

Effect of iron supplementation during early pregnancy on the development of gestational hypertension and pre-eclampsia

Objective

To investigate the association between iron supplementation during early pregnancy and the presence of de novo hypertension after 20 weeks’ gestation (either gestational hypertension or pre-eclampsia).

Study design

Retrospective cohort study.

Methods

This study retrospectively reviewed the medical records of non-anemic pregnant women who received first antenatal care at the Department of Obstetrics and Gynecology, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Bangkok, Thailand, during the June 2009–December 2010 study period. All included women had blood pressure and urine albumin level data that were recorded at each antenatal visit. The study population was divided into one of the two following groups: iron supplementation starting at gestational age (GA)?<?16 weeks (study group) or GA?≥?16 weeks (control group). A comparison of the proportion of de novo hypertension arising after 20 weeks’ gestation was then performed between groups.

Results

Four hundred non-anemic pregnant women were included, with 200 patients allocated to each groups. The overall incidence of de novo hypertension after 20 weeks’ gestation was 10% (40/400), with significantly higher prevalence in the study group than that in the control group [13.5% (27/200) vs. 6.5% (13/200); relative risk: 2.14, 95%, CI 1.22–3.73; p?=?0.008]. None of the women in this study developed anemia at time of delivery. There was no significant difference between groups for GA at delivery, birth weight, or birth asphyxia.

Conclusion

In our study population, iron supplementation before 16 weeks’ GA was significantly associated with increased risk of developing de novo hypertension after 20 weeks’ gestation.

     

Variations in ferritin levels in blood during physiological pregnancy

Iron deficiency anemia is the most frequent haematological pathology in pregnancy. Serum ferritin levels represent the state of iron deposits. Low levels are a sure sign of iron deficiency. At the University of Turin we studied the variations of serum ferritin levels during physiological pregnancy and the sensitivity of routine blood tests with respect to serum ferritin levels. Routine haematological blood values along with ferritin levels were measured in 115 patients throughout pregnancy. The mean serum ferritin level was 56 ng/ml in the first trimester, 27.2 ng/ml in the second and 11.8 ng/ml in the third. The incidences of anemia per trimester was 6.6%, 4.8% and 49% respectively (p less than 0.05, chi squared). Our results show that it is important to evaluate iron deposits early in pregnancy by measuring serum ferritin levels in order to determine the need for iron therapy.     

A "conservative" approach to iron supplementation during pregnancy

A review of current knowledge about iron metabolism during pregnancy and the evidence from various studies on the effects of iron supplementation in pregnancy on maternal, fetal, and infant outcomes suggest that the implicit goal of current recommendations regarding iron supplementation may be to achieve the highest hemoglobin concentration possible. This goal is only weakly related to improved maternal and infant outcomes in the current pregnancy or to improved maternal iron stores long-term. Indeed, the claim that iron supplementation is universally innocuous is shown to be controversial. For women in developed countries who are generally clinically healthy and have access to adequate nutrition, the benefits of iron supplementation are unclear, and there may be risks. Thus, a better "conservative" approach may be that such women do not require routine iron supplementation during pregnancy. The midwifery philosophy of individualizing care based on a woman's history and health status is one that should be taken in approaching the issue of iron supplementation in pregnancy.     

Iron status and iron balance during pregnancy. A critical reappraisal of iron supplementation.

BACKGROUND: Iron supplementation in pregnancy is a controversial issue. The aim of this review was to summarize the results of relevant papers on this subject. METHODS: Placebo-controlled studies on iron treatment in pregnancy were identified from the Cochrane database. RESULTS: Among fertile women, 20% have iron reserves of >500 mg, which is the required minimum during pregnancy; 40% have iron stores of 100-500 mg, and 40% have virtually no iron stores. The demand for absorbed iron increases from 0.8 mg/day in early pregnancy to 7.5 mg/day in late pregnancy. Dietary iron intake in fertile women is median 9 mg/day, i.e. the majority of women have an intake below the estimated allowance of 12 18 mg/day. Iron absorption increases in pregnancy, but not enough to prevent iron deficiency anemia in 20%, of women not taking supplementary iron. Iron-treated pregnant women have greater iron reserves, higher hemoglobin levels, and a lower prevalence of iron deficiency anemia than placebo-treated women both in pregnancy as well as postpartum. Furthermore, children born to iron-treated mothers have higher serum ferritin levels than those born to placebo-treated mothers. An iron supplement of 65 mg/day from 20 weeks of gestation is adequate to prevent iron deficiency anemia. CONCLUSIONS: In order to avoid iron deficiency in pregnancy, prophylactic iron supplement should be considered. Iron supplements may be administered on a general or selective basis. The selective approach implies screening with serum ferritin in early pregnancy, in order to identify women who can manage without prophylactic iron.     

Growth hormone levels in maternal serum during pregnancy

Maternal growth hormone (GH) levels during pregnancy have been variously reported to be suppressed or, more lately, to be increased. In an attempt to clarify this point, maternal GH levels were estimated with two modern GH polyclonal radio-immunoassays (RIAs) and a new monoclonal enzyme-linked immunoassay (ELISA). The Cambridge Medical Diagnostics RIA and the more specific bioMérieux RIA gave similar results in control non-pregnant patients with raised GH levels, while the monoclonal ELISA gave slightly lower values. The bioMérieux assay gave results about 10 times higher than the Cambridge assay during pregnancy, at 12-61 ng/ml at 16-20 weeks and 47-153 ng/ml at 28-39 weeks (total n = 27). These high 'GH' levels did not correlate with maternal levels of prolactin or human placental lactogen. It is presumed that some unknown GH-like molecule(s) are being estimated in this assay, possibly the recently discovered human chorionic GH. That this is not pituitary GH was confirmed by the monoclonal ELISA, by which GH levels were almost undetectable during pregnancy.     

Iron supplementation during pregnancy

192 pregnant women were consecutively randomized to either a vitamin-mineral pill or a vitamin mineral pill with a high iron content in a prospective, open, randomized investigation. The participants were advised about iron-rich foodstuffs twice during pregnancy. Iron status of the mother proved to be without any significance for the outcome of pregnancy. A serum ferritin level of 80 pmol/l in mid-pregnancy followed by a control in the last trimester was suggested as a guide in deciding of whether or not to prescribe supplementary iron during pregnancy.     

Maternal serum adiponectin levels during human pregnancy.

OBJECTIVE: Pregnancy is a unique situation characterized by insulin resistance. The role of adiponectin, an insulin-sensitizing hormone, has not been completely clarified during pregnancy. The aim of this cross-sectional study was to evaluate adiponectin levels during pregnancy and postpartum. STUDY DESIGN: Adiponectin and leptin levels were tested in 80 pregnant women, 20 in each trimester (mean gestational age 10.5+/-1.9; 19.3+/-4.9; 39.3+/-0.8 weeks,) as well as 4 days postpartum. RESULTS: Adiponectin levels during first (13.3+/-3.6 micro g/ml), second (12.6+/-4.4 micro g/ml) and third trimester (11.2+/-3.7 micro g/ml) did not differ and were significantly higher than postpartum levels (8.8+/-2.1 micro g/ml; P<0.0001, P<0.004 and P<0.02, respectively). CONCLUSION: Despite increased insulin resistance during pregnancy, no significant alterations in adiponectin levels were observed. This may imply that the regulation of adiponectin during gestation is altered. The elevated gestational adiponectin levels are consistent with increased 'adiponectin resistance' during pregnancy.     

Iron supplementation during pregnancy

As pregnancy proceeds most women show hematologic changes suggesting iron deficiency. In this study iron dynamics are investigated by determining concentrations of hemoglobin, serum ferritin and serum transferrin in two groups of pregnant women. One group did not receive iron, the other received 105 mg iron/day. Without iron supplementation normal maternal iron stores are almost exhausted during the second and third trimester of pregnancy.     

妊娠期补充铁剂的临床观察

目的观察孕期补充铁剂的效果及对妊娠结局的影响。方法将３６９例孕妇根据补充铁剂前血红蛋白水平分为预防组和治疗组。预防组（血红蛋白≥１１０ｇ／Ｌ）随机分成玛特那１组（９６例,从孕２０～２４周开始口服玛特那）与空白对照组（９５例）。治疗组（血红蛋白＜１１０ｇ／Ｌ）随机分成玛特那２组（９３例）、硫酸亚铁组（５０例）、福乃得组（３５例）。均于孕３６周前开始服药,并分别于服药前查血红蛋白及血清铁蛋白,观察期间每４周复查１次血红蛋白,分娩时分别查母血及脐血血清铁蛋白并观察临床结局。结果玛特那１组服药后母血清铁蛋白明显高于服药前,且明显高于空白对照组（Ｐ＜０．０５）。玛特那２组服药后母血清铁蛋白明显高于服药前（Ｐ＜０．０５）,且明显高于硫酸亚铁组（Ｐ＜０．０５）及福乃得组（Ｐ＜０．０５）。各组的妊娠结局差异无显著性（Ｐ＞０．０５）。结论玛特那可增加孕妇体内的铁储备和有效地改善铁缺乏症状,而对妊娠结局无影响。     

Effect of progesterone supplementation in early pregnancy on the pregnancy outcome after in vitro fertilization

A retrospective cohort study was performed to evaluate IVF clinical pregnancy rates and livebirth rates between patients receiving progesterone supplementation through the first trimester of pregnancy (first trimester protocol) at 12 weeks vs. discontinuation after a positive beta-hCG test 2 weeks after retrieval (luteal protocol) at 4 weeks of pregnancy. A similar rate of clinical pregnancies occurred at 7 weeks (81.8% luteal protocol vs. 85.8% first trimester protocol; P=.49) and for livebirth rates (76.8% luteal protocol vs. 75.0% first trimester protocol; P=.80), but a trend toward a higher rate of pregnancy loss after 7 weeks in the first trimester protocol group occurred (15.5% vs. 4.4%; P=.06), indicating that first trimester progesterone supplementation may support early pregnancy through 7 weeks by delaying miscarriage but does not improve livebirth rates.